Vinyl ester resins and unsaturated polyester resins are well known for having good thermal resistance properties (for example, a Tg of higher than 80° C.) and chemical resistance properties (for example, an acid resistance of less than 1 percent (%) for a time period of 28 days). When conventional epoxy vinyl ester resins and unsaturated polyester resins are cured to form, for example, a composite, the cured resins also display good mechanical properties, but such cured resins lack toughness and are very brittle upon cure. In addition, as the crosslink density or Tg of a cured vinyl ester resin product increases, the cured vinyl ester resin product requires an increase in toughness to provide a useful composite product.
U.S. Patent Application Publication No. 20070265373A1 (US20070265373A1) discloses the use of an amphiphilic block copolymer to toughen epoxy vinyl esters and unsaturated polyester resins; and a curable ester resin composition including (a) an ester resin; (b) at least one copolymerizable reactive monomer; and (c) an amphiphilic block copolymer containing at least one ester resin miscible block segment and at least one ester resin immiscible block segment. When the above ester resin composition is cured, the cured ester resin exhibits an increase in toughness. However, the toughener disclosed in US20070265373A1 is defined as a non-reactive type toughener, i.e., a toughening agent that does not react with the epoxy vinyl ester resin or the unsaturated polyester resin. The above composition containing the “non-reactive type” toughener suffers from the disadvantages of: (1) toughener migration and (2) poor acid resistance.
U.S. Pat. No. 8,021,586B2 (US '586) discloses an amphiphilic block copolymer-toughened epoxy resin and powder coatings made therefrom; including a curable solid resin composition useful for powder coating, wherein the resin composition includes (a) an epoxy resin; (b) an amphiphilic block copolymer containing an epoxy resin miscible block segment and an epoxy resin immiscible block segment; and (c) optionally, a curing agent. US '586 does not disclose a vinyl ester resin or an unsaturated polyester resin. Also, the above amphiphilic block copolymer is a “non-reactive” toughener; and is not a carboxyl group terminated amphiphilic block copolymer.
U.S. Patent Application Publication No. 2011/0319523A1 (US2011/0319523A1) discloses a thermosettable composition containing a combination of an amphiphilic block copolymer and a polyol; and a cured thermoset product prepared from the thermosettable composition. The thermosettable composition includes (a) an amphiphilic block copolymer, (b) a polyol, (c) an epoxy resin having oxirane rings, (d) an anhydride hardener containing an anhydride ring, and (e) a catalyst. US2011/0319523A1 does not teach a vinyl ester resin or an unsaturated polyester resin; or the use of a carboxyl group terminated amphiphilic block copolymer as a toughener.
U.S. Patent Application Publication No. 2011/0114257A1 (US2011/0114257A1) discloses reaction products based on an amphiphilic block copolymer and the use of an amphiphilic block copolymer as an impact modifier. The amphiphilic copolymer is based on ethylene oxide/butylene oxide (EO/BO) and used as an impact modifier component; and the final composition product is used for adhesive applications. US2011/0114257A1 does not teach: (1) a vinyl ester resin or the use of a carboxyl group terminated amphiphilic block copolymer as a toughener; (2) the synthesis of a vinyl ester resin using as toughener reacted into the backbone of the resin; or (3) a resin having excellent acid resistance performance or other beneficial properties other than toughness.
In Journal of Polymer Science, Part B: Polymer Physics, 2001, 39(23), 2996-3010, the authors of this article disclose that the use of a poly(ethylene oxide)-b-poly(ethylene-alt-propylene) (PEO-PEP) diblock copolymer provides micelle structures in cured epoxy resin thermoset systems, and that the block copolymers can self-assemble into vesicles and spherical micelles which can significantly increase the fracture resistance performance of the cured thermoset. The above article does not teach a vinyl ester resin or the use of a carboxyl group terminated amphiphilic block copolymer as a toughener. And, the above article does not teach the synthesis of a vinyl ester resin using as toughener reacted into the backbone of the resin. In addition, the above article does not disclose a resin having excellent acid resistance performance or other beneficial properties other than toughness.